Note: On the SheevaPlug, the onboard NAND flash is called /dev/mtdblock2. You might want to use it as a swap partition, as it would be faster than your SD card or USB drive.
Note: if the command free shows that the swap is not activated (displays 0) you should check the /etc/fstab fiel and make sure that it points to your swap partition. Then either reboot the plug or
swapon /dev/<partition>
= Customize and Extend =
If you need customizations for your device, you can install the [http://fedoraproject.org/wiki/Architectures/ARM/CrossToolchain ARM cross compilation toolset] to compile things like the kernel, multimedia libraries, etc. etc.